I. Field of the Invention
The present invention relates generally to direct injection internal combustion engines and, more particularly, to a fuel system for such engines which reduces the stress imposed on the fuel system components.
II. Description of Related Art
Direct injection internal combustion engines are becoming increasingly popular in the automotive industry due in large part to their high efficiency and fuel economy. In such a direct injection engine, at least one fuel injector is mounted in a bore formed in the engine block which is open directly to the internal combustion chamber. A high pressure fuel rail is coupled to the fuel injector which, when open under control of the engine control unit, injects fuel directly into the internal combustion engine.
Since the injectors of the direct injection engine are open directly to the internal combustion chamber, the fuel in the fuel rails must necessarily be maintained at a relatively high pressure. Typically, a cam driven piston pump is used to pressurize the fuel rail.
One disadvantage of direct injection internal combustion engines, however, is that the fuel system components move slightly relative to each other in response to the high pressure fuel injection pulses and pump pulses. This, in turn, imparts stress on the fuel system components which can result in cracking or other component failure.